This invention relates to nuclear power, and more particularly, to the consolidated storage of nuclear fuel that has been removed from typical light-water nuclear power reactors.
Rather than storing entire fuel assemblies in side-by-side relationship in spent fuel pools, efforts toward fuel consolidation attempt to pack individual fuel rods in the tightest possible array, eliminating the spacing and support structure associated with entire fuel assemblies. Reduction of the space between fuel rods not only enables a higher density of fuel rods per available storage area in the fuel pool, it also provides a neutronics benefit in that the reduction in moderator-to-fuel atom ratio keeps the reactivity of the consolidated fuel at a safe level.
Although the benefits of consolidated fuel storage are well recognized, the difficulties associated with the consolidation process itself have inhibited adoption of fuel consolidation techniques by the power plant operators. These difficulties stem from the requirement that the fuel assemblies must be disassembled to remove the individual fuel rods, and the fuel rods must be rearranged in a closely packed array that can be convienently handled. Since the spent fuel rods are highly radioactive, these operations must be performed remotely under water depths up to forty feet.